Neither of these cards will support multiple monitors. Both have one DVI port, I think.

The difference between PCI, PCI Express and AGP: don't bother with regular PCI. It shares the bus with all other PCI devices, meaning that your video card will compete with other system components for resources. Neither PCI Express or AGP suffer from this limitation.

I think this makes your choice of cards easy--from what I remember, your motherboard supports only PCI-Exp or AGP, not both. If you're buying a new motherboard or new system, I'd go PCI express. It is faster.

Either one of the cards you listed are available for less than the amount you posted. Look around a bit, you should be able to find them around the $150 mark. Also, make sure you look at the system specs for the game you want to play; the specs will tell you how much video RAM is recommended.

If you're buying a new card for gaming, and you're not planning ony buying a new card anytime soon, you might want to consider getting a 256 meg card.